Review Question - QID 217459

A 69-year-old female presents for evaluation secondary to pain at multiple sites throughout the body. Radiographs of the upper and lower extremities demonstrate multiple lytic lesions. There is concern for multiple myeloma. The patient has a serum protein electrophoresis and a bone marrow aspiration performed. Of the values provided, which of the following is the minimum amount of plasmacytosis that would indicate a positive bone marrow aspiration for making the diagnosis of multiple myeloma in this patient?